hold the sun in right hand, and hold the earth in the left hand, feel the attraction force?

that is gravity. what's its speed? zero.

force has direction, strength, but force has no speed. only moving matter has speed.

if you wave right hand, earth will wave in your left hand due to gravity. 

but the strange thing is, there is a time delay between the two hands. 

gravity conducts/transfers/moves at light speed. 

only moving force has speed. tension, attraction, pressure, rest forces have no speed.


when you waving right hand, that waving force/energy follow the gravity line teleported to left hand.

without gravity/force, there is no energy transforming. force is the carrier/messenger/conductor of energy.

the sun does not shoot out energy/photon into space. there is no photon, no mechanism.

the sun only shares its thermal energy with matters surround. 

the forces between the sun and planets are the pipelines.

namely f=G x m1m2/rr and f=Ke x q1q2/rr.

every electron on the atoms on the surface of the moon is repelled by every electron on the line of sight surface atoms on earth. Those electrons conduct light energy.